He has apologized for sending inappropriate messages to women and then lying about it

New York (CNN) -- U.S. Rep. Anthony Weiner, who has been under fire after admitting to inappropriate communications with women online, has decided to seek treatment "to focus on becoming a better husband and healthier person," his spokeswoman said Saturday.

While the New York congressman seeks treatment at an undisclosed location, he will take a "short leave of absence" from Congress, Risa Heller said in a statement.

A Democratic source, familiar with conversations among Weiner and Democratic leadership about his fate, did not know what specific type of treatment Weiner, 46, would undergo.

House Minority Leader Nancy Pelosi and the chairmen of the Democratic National Committee and the Democratic Congressional Campaign Committee called for Weiner to step down in separate statements earlier Saturday.

Weiner's decision to seek treatment and take a leave was not enough to satisfy Pelosi, who wants him to step down, a Pelosi aide told CNN.

"Congressman Weiner has the love of his family, the confidence of his constituents and the recognition that he needs help. I urge Congressman Weiner to seek that help without the pressures of being a member of Congress," Pelosi said earlier.

DCCC Chair Steve Israel also wished Weiner well in his personal life, but said that the scandal has "become an insurmountable distraction" to the House.

"The behavior he has exhibited is indefensible and Representative Weiner's continued service in Congress is untenable," DNC Chairwoman Debbie Wasserman Schultz said, also calling it a distraction.

According to the Democratic source, leaders decided it was time to tell Weiner to resign because they "don't want to go into a third week with a story that brings disgrace on the House and not talk about our agenda."

This same source said Weiner responded that he doesn't want to make a decision until his wife, Huma Abedin, returns from a trip. Abedin, a senior aide to Secretary of State Hillary Clinton, is traveling with her in Africa and is scheduled to return early Thursday.

"Congressman Weiner takes the views of his colleagues very seriously and has determined that he needs this time to get healthy and make the best decision possible for himself, his family and his constituents," Heller said.

The statements come as Delaware authorities are investigating contact between a local teen and Weiner.

"Detectives were made aware of alleged contact between Congressman Anthony Weiner and an area teen," New Castle County Police said in a statement. "Detectives have conducted an interview with the teen and she has made no disclosure of criminal activity nor inappropriate contact by the congressman."

Pressed for answers on the Delaware allegations as he ran errands in the New York City borough of Queens on Saturday, Weiner told reporters: "Nothing explicit, nothing indecent. Absolutely nothing inappropriate."

A senior Democratic official told CNN that the decision to call for Weiner's resignation had "been in the works for several days" and the discussions "between the political committees resulted in an internal Saturday morning deadline for him to resign on his own."

The official, who spoke on condition of anonymity because of the sensitivity of the matter, said the decision "was decided before the Delaware news broke."

Weiner admitted this week that he engaged in sexually tinged communications with women and lied about it.

The congressman publicly apologized Monday for exchanging "messages and photos of explicit nature with about six women in the last three years." He said he communicated with women through Facebook, Twitter, e-mail and, occasionally, on the phone.

"I don't know the exact ages of the women ... at least to the best of my knowledge, they were all adults, and they were engaging in conversations consensually," Weiner said Monday. "All I know is what they published about themselves in social media."

Weiner also said he never met any of the women in person.

Wednesday's publication online of an explicit photo that a conservative blogger claims shows Weiner's genitals was the latest twist in the scandal. Andrew Breitbart, whose biggovernment.com website broke the story of Weiner's sexting, said the photo came from a woman who told him Weiner sent it to her.

Weiner acknowledged Monday that such an X-rated photo of him could exist.

On Saturday, Weiner said, "I've made some serious mistakes and I'm trying to redeem myself," adding that his "remarkable" wife is doing well.

"I'm trying to get back to work," said Weiner, who, before the scandal broke, was best known for a passionate, theatrical rant on the House floor over a bill that funded health care costs for 9/11 first responders.

Among other things, the congressman can point to a Marist College poll released Thursday showing that a majority of registered voters in his district -- 56% -- don't believe he should step down.

Only 33% believe he should go.

Assuming Weiner stays, the question now becomes whether the House ethics panel will heed calls for an investigation from top Democrats. Weiner has said he would welcome an ethics probe.

The code of conduct for members of Congress calls for them to conduct themselves "at all times in a manner that shall reflect creditably on the House." However, ethics experts say legislators are rarely, if ever, disciplined for violating that rule alone.

Using government technology such as telephones and computers for his sexting could be another story.

Weiner has said he used his personal BlackBerry and home computer, but added: "I don't have the knowledge of every last communication, but I don't believe that I used any government resources."

Weiner was first elected to the House in 1998 after his political mentor, then-Rep. Chuck Schumer, decided to run for the Senate. He has been a reliable liberal voice for the solidly Democratic 9th District, which encompasses parts of Brooklyn and Queens. He ran unsuccessfully in the Democratic mayoral primary race in 2005 and was mentioned as a candidate for 2013.

Schumer said Saturday he was "heartbroken" about the situation.

"For those of us who are longtime friends of Anthony Weiner his wrongful behavior is distressing and saddening," the senator said in a statement. "It's clear he needs professional help and I am glad he is seeking it."